System and Method for Coordinating Multiple Wireless Communications Devices in a Wireless Communications Network

ABSTRACT

A method for allocating radio resources by a coordinating wireless communications device in a wireless communications network including a plurality of wireless communications devices includes: obtaining a plurality of supported narrow-band channels in the wireless communications network; selecting a primary channel from the supported narrow-band channels and using the primary channel to communicate with the plurality of wireless communications devices; organizing the plurality of wireless communications devices into one or more communication groups; and assigning one of the one or more communication group a non-overlapping operating channel for multi-user multiple-input multiple-output (MU MIMO) communication with the coordinating wireless communications device.

This application is a continuation-in-part application of co-pendingapplication Ser. No. 14/630,693, filed on Feb. 25, 2015, the contents ofwhich are incorporated herein by reference.

TECHNICAL FIELD

The disclosure relates in general to a wireless communications network.

BACKGROUND

In a WLAN (wireless local area network) system, such as IEEE802.11ac, an802.11ac BSS (basic service set) can employ spatial diversity technique,DL-MU-MIMO (down-link multi-user multi-input multi-output), to increaseits throughput. A high-rate wide band wireless access point (AP)aggregating a plurality of narrow band channels is able to manage widerbandwidth channels and manage wireless stations (STA) of differentgenerations occupying different channel bandwidth. By spatial domaindiversity, an 802.11ac AP coalesces one or more narrow channels (20 MHz)into one wide band channel (for example, 160 MHz).

The 802.11ac AP is capable of supporting channels of wider bandwidth, upto 160 MHz. The 802.11ac BSS supports a variety of 802.11 series STAsincluding legacy STAs (for example, 802.11b/g/n STA) and non-legacy STA(for example, 802.11ac STA).

The bandwidth supported by STAs of an 802.11ac BSS may range from 20 MHzup to 160 MHz. For example, the bandwidth supported by 802.11b/g STA is20 MHz; the bandwidth supported by 802.11n STA may be 40 MHz; and thebandwidth supported by 802.11ac STA may be 80 MHz or 160 MHz. Therefore,the channel bandwidth available for each MU-MIMO group is gated by theparticipating STAs with the smallest channel bandwidth.

Even though the high-rate wide band wireless environment provides widerbandwidth, the actual channel bandwidth utilized is limited by the STAhaving the smallest channel bandwidth. As a result, the radio resourceis underutilized.

For example, the high-rate wide band wireless access point typicallyequips with multiple antennas and the multi-user multi-inputmulti-output (MU-MIMO) scheme is adopted to improve the performance ofthe wireless network by allowing simultaneous transmissions to a groupof STAs. But, in the current MU-MIMO scheme, channels not involved inthe current MU-MIMO operation are left un-utilized.

FIG. 1A (PRIOR ART) shows channel bandwidth utilization in the currentDL-MU-MIMO scheme. For example, the AP 110 and the STA 121 both supportchannels 1˜8; the STA 122 supports channel 3; and the STA 123 supportschannels 3 and 4. Assuming that the STAs 121˜123 are of the same group.As shown in FIG. 1A, only channel 3 is utilized when the group(including the STA 121˜123) is active. In other words, channels 1˜2 and4˜8 are unutilized and wasted. So, the radio resource is underutilized.

Further, in coexistence with legacy OBSS (overlap BSS), the 802.11ac APcan not actively manage its channel. FIG. 1B shows that the AP can notactively manage its channel due to in coexistence with legacy OBSS. Asshown in FIG. 1B, OBSSs 131 and 132 occupying channel 3 (for example, achannel being 20 MHz) and channels 5˜6 (40 MHz) may prevent the 802.11acAP from acquiring a wider channel. The 802.11ac AP is capable ofcoalescing 8 channels to start a BSS, but there are only 2 contiguouschannels (40 MHz) available.

BRIEF SUMMARY

Embodiments of a system and a method for coordinating multiple wirelesscommunications devices in a wireless communications network aredisclosed for improving radio resource utilization.

An exemplary embodiment of the disclosure provides a method forallocating radio resources by a coordinating wireless communicationsdevice in a wireless communications network including a plurality ofwireless communications devices, the method including: obtaining aplurality of supported narrow-band channels in the wirelesscommunications network; selecting a primary channel from the supportednarrow-band channels and using the primary channel to communicate withthe plurality of wireless communications devices; organizing theplurality of wireless communications devices into one or morecommunication groups; assigning one of the one or more communicationgroups a non-overlapping operating channel for multi-user down-linkmultiple-input multiple-output (MU DL MIMO) operation with thecoordinating wireless communications device, wherein the non-overlappingoperating channel contains at least two of the plurality of supportednarrow-band channels in a coalesced manner; and assigning another one ofthe one or more communication groups another non-overlapping operatingchannel for multi-user up-link multiple-input multiple-output (MU ULMIMO) operation with the coordinating wireless communications device,wherein the another non-overlapping operating channel contains at leasttwo of the plurality of supported narrow-band channels in a coalescedmanner; wherein the plurality of wireless communications devices in theone and the another one of the one or more communication groupscommunicate with the coordinating wireless communications deviceconcurrently.

Another exemplary embodiment of the disclosure provides a wirelesscommunications network including: a coordinating wireless communicationsdevice; and a plurality of wireless communications devices, coordinatedby the coordinating wireless communications device. The coordinatingwireless communications device obtains a plurality of supportednarrow-band channels in the wireless communications network. Thecoordinating wireless communications device selects a primary channelfrom the supported narrow-band channels and using the primary channel tocommunicate with the plurality of wireless communications devices. Thecoordinating wireless communications device organizes the plurality ofwireless communications devices into one or more communication groups.The coordinating wireless communications device assigns one of the oneor more communication groups a non-overlapping operating channel formulti-user down-link multiple-input multiple-output (MU DL MIMO)operation with the coordinating wireless communications device, whereinthe non-overlapping operating channel contains at least two of theplurality of supported narrow-band channels in a coalesced manner. Thecoordinating wireless communications device assigns another one of theone or more communication groups another non-overlapping operatingchannel for multi-user up-link multiple-input multiple-output (MU ULMIMO) operation with the coordinating wireless communications device,wherein the another non-overlapping operating channel contains at leasttwo of the plurality of supported narrow-band channels in a coalescedmanner, wherein the plurality of wireless communications devices in theone and the another one of the one or more one communication groupcommunicate with the coordinating wireless communications deviceconcurrently.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the disclosed embodiments, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A (PRIOR ART) shows a channel bandwidth utilization in the currentDL-MU-MIMO scheme.

FIG. 1B (PRIOR ART) shows that an AP can not actively manage its channelutilization due to in coexistence with legacy OBSS.

FIG. 2 shows MU DL implementations according to the embodiment of thedisclosure.

FIG. 3 shows STA-to-STA(s) MU with FDM in the embodiment of thedisclosure.

FIG. 4 shows the migration of OBSS.

FIG. 5 shows herding of STAs in the embodiment of the disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

The disclosure describes a method and system for managing a wirelesscommunications network having at least an access point (AP) and aplurality of mobile stations (STA).

In the following, a wide Band Access Point (WBAP) refers to a wirelessaccess point capable of supporting n narrow band channels (n being anatural number). A narrow band channel is for example but not limited by20 MHz. Also, AP may be referred as a coordinating wirelesscommunications device; and a STA may be referred as a wirelesscommunications device. An operating channel refers to a channelincluding one or more non-overlapping narrow band channels. Anon-overlapping operating channel refers to an operating channel thatdoes not contain any narrow band channel which overlaps with any otheroperating channel.

The AP coalescing available narrow band channels form a BSS supportingwideband channel and select one narrow band channel as the primarychannel. The AP and the STAs exchange management and control informationof the wireless communications network through the primary channel. Anarrow band channels is selected by the AP as the primary channel inaccordance with a first pre-determined rule. After the AP selects theprimary channel, the AP announces the primary channel to all STAs.

The first pre-determined rule determining the number of thenon-overlapping operating channels is for example but not limited tobased on parameters selected from a group including the availability ofthe number of narrow-band channels, the level of the interference ofeach narrow-band channel, the supported narrow-band channels of each ofthe STAs.

The bandwidth of the wideband channel is determined by the AP based onchannel conditions and AP/STA capabilities. All STAs of the BSS receiveone or more duplicated beacons covering up to the wideband channel sentby the AP.

Also, in the disclosure, a MU DL-FDM (multi-user down-link frequencydomain multiplexing) is disclosed. The AP manages channel selection ofmember STAs which may include legacy STA(s) (for example, 802.11b/g/nSTA) and non-legacy STA(s) (for example but not limited to 802.11acSTA). Each non-legacy STA operates on a group of one or more narrow bandchannels which form a non-overlapping operating channel. One or morenon-overlapping operating channels may operate concurrently.

The AP organizes the STAs into more than one communication groups. TheSTAs in each communication group occupy one or more narrow band channelsand the more than one communication group resides in the narrow bands.The constituents of each communication group are determined staticallyor dynamically by the AP in accordance with a second pre-determinedrule. The AP may re-organize the STAs adaptively to improve theperformance of the wireless communication network.

The second pre-determined rule determining the constituents of eachcommunication group and determining which non-overlapping operatingchannel the STA is assigned to is based on algorithms selected from agroup comprising best fit algorithm, first fit algorithm, the populationof non-overlapping operating channel, application requirement, whereinthe assignment of operation channel is done either statically ordynamically.

The AP changes the channel width occupied by the communication group inaccordance with parameters such as but not limited to the bandwidthusage, and bandwidth requirements of applications deployed in thecommunications group.

The STAs of the more than one communication groups operate concurrentlywith or without the direct management of the AP. In other words, thetransmission of data from the STAs to other STA(s) is either directly orrelayed by the AP.

The AP directs the migration of the STAs of the communication group fromone frequency band to another.

Now describe how to set up operating channels and groups of STAs.

The WBAP establishes a wireless communications network by sending outinvitation messages embedded in radio frames (such as beacon) ormanagement frames to STAs or by receiving unsolicited requestingmessages from STAs on the primary channel. Beacon is repeated on everynarrow band channel supported by the AP. The receiving of the invitationmessages or sending of requesting messages starts the association andauthentication process for the STA (the STA capable of occupying mnarrow band channels, m being a natural number and m≦n). An STA joinsthe wireless communications network after exchanging the capabilityinformation with the AP and completing the association andauthentication process.

Based on a predetermined allocation algorithm, the WBAP instructs theSTA to occupy the p narrow band channels, where p being a natural numberand p≦m≦n. The STA uses the primary channel to exchange managementmessages with the WBAP.

If the STA is the first to join an infrastructure wireless network, anexemplary allocation algorithm employed by the WBAP is a first-fitalgorithm, i.e., WBAP selects the first set of contiguous p narrow bandchannels having the least amount of noise for the WBAP and the STA.Another exemplary allocation algorithm employed by the WBAP is a bestfit algorithm.

If the STA joins the infrastructure wireless network already having qSTAs (q being a natural number), the WBAP statically or dynamicallydecides the channel assignment according to, for example but not limitedto, the following factors: the number of occupants of an operatingchannel, number of narrow band channels supported by each STA, thebandwidth consumption of active flows which in embodiment is based onQoS (Quality of Service) setting of the flow, and overall loading of theoperating channels. For example, if a 40 MHz STA is to join theinfrastructure wireless network, the WBAP may assign the 40 MHz STA to aSTA group occupying 40 MHz or 80 MHz, for small effect on the overallloading of the operating channels.

In one embodiment, the WBAP partitions the n narrow band channels into r(r being a natural number) non-overlapping operating channels and theWBAP divides the STAs into s groups (s being a natural number) forexample according to the first predetermined rule.

For example, the WBAP may partition 160 MHz into (1) two 80 MHznon-overlapping operating channels; (2) one 80 MHz non-overlappingoperating channels and two 40 MHz non-overlapping operating channels;(3) one 80 MHz non-overlapping operating channels, one 40 MHznon-overlapping operating channels and two 20 MHz non-overlappingoperating channels; (4) one 80 MHz non-overlapping operating channelsand four 20 MHz non-overlapping operating channels; (5) four 40 MHznon-overlapping operating channels; (6) three 40 MHz non-overlappingoperating channels and two 20 MHz non-overlapping operating channels;(7) two 40 MHz non-overlapping operating channels and four 20 MHznon-overlapping operating channels; (8) one 40 MHz non-overlappingoperating channels and six 20 MHz non-overlapping operating channels; or(9) eight 20 MHz non-overlapping operating channels. The channelbandwidth of the non-overlapping operating channels may be different orthe same. Also, the number of STAs in each group may be different or thesame.

In another embodiment, the STAs form groups, each group having a channelbandwidth determined by the channel capacity of the STAs of each groupor determined by the AP. If the sum of the channel bandwidth of allgroups is greater than n narrow band channels, then the WBAP decides thechannel bandwidth of each non-overlapping operating channel according tothe QoS requirements of each of the groups and the sum of the channelbandwidth of all non-overlapping operating channels must be equal to orsmaller than sum of n narrow band channels. On the contrary, if the sumof the channel bandwidth of all groups is not greater than n narrow bandchannels, then the channel bandwidth of each group is determined by thechannel capacity of the STAs of each group.

Yet in another embodiment, if the WBAP learns that one of the STAsestablishes a direct link session with one or more other STAs, i.e., themessages are exchanged directly between the STA and the one or moreother STAs without relaying through the WBAP, then the WBAP may decideto re-partition the n narrow band channels and create a non-overlappingoperating channel for the STA and the one or more other STAs (thosehaving a direct link session). The re-partitioning of the n narrow bandchannel may be, for example but not limited by, based on the exemplarypartitioning algorithms described above. There are methods known topeople skilled in the art to migrate the direct link STAs to the newlysetup operating channel in a timely fashion.

Yet in another embodiment, the WBAP may learn from the QoS setting ofthe flows that more than one set of STAs occupying one or more operatingchannels exchanges data interactively, i.e. the data are sent inping-pong fashion between two STAs. For example, the exchange ofrequest/response packets or the exchange of data/acknowledge packets.The WBAP sets up a dedicated time period for the more than one set ofSTAs occupying one or more operating channels for scheduled access ofthe radio channel. The operating channels operate synchronously.

Now data exchanges for STAs in operating channels are described.

The messages exchanged in one operating channel are either directlyamong STAs occupying the operating channel or relayed through the WBAP.A message may be sent to an STA (i.e. uni-cast), to one or more STAs(i.e. multicast), or to all STAs (i.e. broadcast) in the operatingchannel. A message sent from an STA in one operating channel may berelayed to another STA in a different operating channel by the WBAP. TheWBAP coordinates the operation of non-overlapping operating channels.The concurrent operations of non-overlapping operating channels areeither synchronous or asynchronous.

Every time an STA has data ready for other STA(s), the STA obtainstransmission opportunities by either (1) contending for the access right(i.e. a carrier sensing collision avoidance implementation) for examplebut not limited to according to protocol such as 802.11 CSMA/CA, or (2)requesting the WBAP to grant the access right (i.e. a request-basedimplementation), or (3) a hybrid implementation which combines theprevious two implementations. In other words, in the disclosure, thereare at least three channel access implementations.

When STAs of a non-overlapping operating channel access the radiochannel by for example but not limited by one of the channel accessimplementations described above, without having the WBAP to synchronizethe channel access with that of another non-overlapping operatingchannel, the non-overlapping operating channels operate asynchronously.Otherwise, the non-overlapping operating channels operate synchronouslywith other operating channels.

The WBAP decides for each non-operating channel whether it shouldoperate synchronously or asynchronously according to one or moreexemplary coordinating algorithms. In one exemplary coordinatingalgorithm, the WBAP places the groups of STAs establishing direct linksession in one of the operating channels operating asynchronously. Theremaining operating channels operate synchronously coordinated by theWBAP.

Further, in the embodiment, the AP may support multi-user down-link (MUDL) traffic by the following implementations, MU DL-MIMO; MU DL-FMD orMU DL-OFDMA (Orthogonal Frequency-Division Multiple Access).

To implement MU DL-MIMO, the AP selects a sub-set of coalesced channelsfor DL-MIMO operation. To implement MU DL-FDM, the AP instructs targetSTAs to switch to corresponding channels and DL traffic is sent to thecorresponding channels for load balance. To implement MU DL-OFDMA, theAP selects a sub-set of coalesced channels for OFDMA-based DL-MIMO. FIG.2 shows MU DL implementations according to the embodiment of thedisclosure.

Further, in the embodiment of the disclosure, STA-to-STA(s) MU with FDMis disclosed. An STA may establish direct link session (DLS) with one ormore destination STAs. The STA sends a request message to the AP forrequesting channel time. The request message also includes channelbandwidth and transmission opportunity (TXOP). The AP may grant therequest and instruct the participating STAs to switch to the subset ofchannel with request bandwidth.

FIG. 3 shows STA-to-STA(s) MU with FDM in the embodiment of thedisclosure. As shown in FIG. 3, the STA 310 establishes a direct linksession with the STA 311, without relaying through AP 320. Besides, theSTA 312 communicates with the STA 313 with relaying through AP 320. TheSTA 314 communicates with the STAs 315˜317 in spatial domain diversity.

Further, in the embodiment of the disclosure, the AP instructs otherOBSSs to move to other channel(s) in order to obtain contiguouschannels. Please refer to FIG. 4, which shows the migration of OBSS. TheOBSS 1 occupies channel 3; and the OBSS 2 occupies channels 5˜6. Inresponse to AP's instruction, for example but not limited to, the OBSS1moves to channel 6 and the OBSS 2 moves to channels 7˜8, so thatcontiguous channels 6˜8 for the OBSSs are obtained. Further, the APshall scan all channels, exchange channel information with STAs and APsof OBSSs.

Further, in the embodiment of the disclosure, upon receiving beaconsfrom the AP, STAs join the BSS via the primary channel for STA herding.FIG 5 shows herding of STAs in the embodiment of the disclosure. Asshown in FIG. 5, before receiving beacons from the AP 510, the STAs511˜514 occupy channels 1˜8, channels 2, channels 3˜4 and channels 7˜8respectively; and in other words, the STA 512˜514 are not herded. Uponreceiving beacons from the AP, the STA 512 moves to occupy channel 3;the STA 513 moves to occupy channels 2˜3; and the STA 514 moves tooccupy channels 3˜4. So, the STAs 511˜514 are herded via the primarychannel 3.

Further, in the embodiment of the disclosure, the AP may supportmulti-user down-link (MU DL) operation and multi-user up-link (MU UL)operation synchronously by the following implementations, such as MU DLMIMO and MU UL MIMO; MU DL OFDMA and MU UL OFDMA; or MU DL FDM and MU ULFDM.

To implement MU DL MIMO and MU UL MIMO, the AP selects a sub-set ofcoalesced channels for MU DL MIMO, and selects another sub-set ofcoalesced channels for MU UL MIMO. To implement MU DL OFDMA and MU ULOFDMA, the AP selects a second sub-set of coalesced channels for MU DLOFDMA, and selects another second sub-set of coalesced channels for MUUL OFDMA. To implement MU DL FDM and MU UL FDM, the AP selects a thirdsub-set of coalesced channels for MU DL OFDMA, and selects another thirdsub-set of coalesced channels for MU UL OFDMA.

Further, in the embodiment, the allocation of the radio resource in eachoperating channel is a local decision without the intervention of theAP. The operating channel operates asynchronously with other operatingchannels.

Further, in the embodiment, the allocation of the radio resource of theone or more operating channels is managed and coordinated by AP. Theoperating channels operate synchronously.

It will be appreciated by those skilled in the art that changes could bemade to the disclosed embodiments described above without departing fromthe broad inventive concept thereof. It is understood, therefore, thatthe disclosed embodiments are not limited to the particular examplesdisclosed, but is intended to cover modifications within the spirit andscope of the disclosed embodiments as defined by the claims that follow.

What is claimed is:
 1. A method for allocating radio resources by acoordinating wireless communications device in a wireless communicationsnetwork including a plurality of wireless communications devices, themethod comprising: obtaining a plurality of supported narrow-bandchannels in the wireless communications network; selecting a primarychannel from the supported narrow-band channels and using the primarychannel to communicate with the plurality of wireless communicationsdevices; organizing the plurality of wireless communications devicesinto one or more communication groups; assigning one of the one or morecommunication groups a non-overlapping operating channel for multi-userdown-link multiple-input multiple-output (MU DL MIMO) operation with thecoordinating wireless communications device, wherein the non-overlappingoperating channel contains at least two of the plurality of supportednarrow-band channels in a coalesced manner; and assigning another one ofthe one or more communication groups another non-overlapping operatingchannel for multi-user up-link multiple-input multiple-output (MU ULMIMO) operation with the coordinating wireless communications device,wherein the another non-overlapping operating channel contains at leasttwo of the plurality of supported narrow-band channels in a coalescedmanner; wherein the plurality of wireless communications devices in theone and the another one of the one or more communication groupscommunicate with the coordinating wireless communications deviceconcurrently.
 2. The method of claim 1, wherein the selecting step isbased on parameters selected from a group comprising an availabilitynumber of the narrow-band channels, an interference level of each of thenarrow-band channels and the respective supported narrow-band channelssupported by each of the wireless communications device.
 3. The methodof claim 1, wherein the organizing step is based on algorithms selectedfrom a group comprising a best fit algorithm, a first fit algorithm, apopulation of non-overlapping operating channel and applicationrequirements.
 4. The method of claim 1, wherein the assigning step iseither static or dynamic.
 5. The method of claim 1, wherein in theassigning step, channel access of the allocated wireless communicationsdevice is determined based on a carrier sensing collision avoidancealgorithm, a request based algorithm or a mix thereof.
 6. The method ofclaim 1, further comprising, assigning a second one of the one or morecommunication group another non-overlapping operating channel formulti-user down-link orthogonal frequency-division multiple access (MUDL OFDMA) operation with the coordinating wireless communicationsdevice; and assigning another second one of the one or morecommunication group another non-overlapping operating channel formulti-user up-link orthogonal frequency-division multiple access (MU ULOFDMA) operation with the coordinating wireless communications device,wherein the plurality of wireless communications devices in the secondone and the another second one of the one or more communication groupscommunicate with the coordinating wireless communications deviceconcurrently.
 7. The method of claim 1, further comprising, assigning asecond one of the one or more communication group anothernon-overlapping operating channel for multi-user down-link frequencydomain multiplexing (MU DL FDM) operation with the coordinating wirelesscommunications device; and assigning another second one of the one ormore communication group another non-overlapping operating channel formulti-user up-link frequency domain multiplexing (MU UL FDM) operationwith the coordinating wireless communications device, wherein theplurality of wireless communications devices in the second one and theanother second one of the one or more communication groups communicatewith the coordinating wireless communications device concurrently.
 8. Awireless communications network including: a coordinating wirelesscommunications device; and a plurality of wireless communicationsdevices, coordinated by the coordinating wireless communications device;wherein: the coordinating wireless communications device obtains aplurality of supported narrow-band channels in the wirelesscommunications network; the coordinating wireless communications deviceselects a primary channel from the supported narrow-band channels andusing the primary channel to communicate with the plurality of wirelesscommunications devices; the coordinating wireless communications deviceorganizes the plurality of wireless communications devices into one ormore communication groups; and the coordinating wireless communicationsdevice assigns one of the one or more communication groups anon-overlapping operating channel for multi-user down-linkmultiple-input multiple-output (MU DL MIMO) operation with thecoordinating wireless communications device, wherein the non-overlappingoperating channel contains at least two of the plurality of supportednarrow-band channels in a coalesced manner; and the coordinatingwireless communications device assigns another one of the one or morecommunication groups another non-overlapping operating channel formulti-user up-link multiple-input multiple-output (MU UL MIMO) operationwith the coordinating wireless communications device, wherein theanother non-overlapping operating channel contains at least two of theplurality of supported narrow-band channels in a coalesced manner,wherein the plurality of wireless communications devices in the one andthe another one of the one or more one communication group communicatewith the coordinating wireless communications device concurrently. 9.The wireless communications network of claim 8, wherein the coordinatingwireless communications device selects the primary channel based onparameters selected from a group comprising an availability number ofthe narrow-band channels, an interference level of each of thenarrow-band channels and the respective supported narrow-band channelssupported by each of the wireless communications device.
 10. Thewireless communications network of claim 8, wherein the coordinatingwireless communications device organizes the plurality of wirelesscommunications devices based on algorithms selected from a groupcomprising a best fit algorithm, a first fit algorithm, a population ofnon-overlapping operating channel and application requirements.
 11. Thewireless communications network of claim 8, wherein the coordinatingwireless communications device assigns either statically or dynamically.12. The wireless communications network of claim 8, wherein in assign bythe coordinating wireless communications device, channel access of theallocated wireless communications device is determined based on acarrier sensing collision avoidance algorithm, a request based algorithmor a mix thereof.
 13. The wireless communications network of claim 8,wherein the coordinating wireless communications device assigns a secondone of the one or more communication group another non-overlappingoperating channel for multi-user down-link orthogonal frequency-divisionmultiple access (MU DL OFDMA) operation with the coordinating wirelesscommunications device; and the coordinating wireless communicationsdevice assigns another second one of the one or more communication groupanother non-overlapping operating channel for multi-user up-linkorthogonal frequency-division multiple access (MU UL OFDMA) operationwith the coordinating wireless communications device, wherein theplurality of wireless communications devices in the second one and theanother second one of the one or more communication groups communicatewith the coordinating wireless communications device concurrently. 14.The wireless communications network of claim 8, wherein the coordinatingwireless communications device assigns a second one of the one or morecommunication group another non-overlapping operating channel formulti-user down-link frequency domain multiplexing (MU DL FDM) operationwith the coordinating wireless communications device; the coordinatingwireless communications device assigns another second one of the one ormore communication group another non-overlapping operating channel formulti-user up-link frequency domain multiplexing (MU UL FDM) operationwith the coordinating wireless communications device, wherein theplurality of wireless communications devices in the second one and theanother second one of the one or more communication groups communicatewith the coordinating wireless communications device concurrently.